Adjudicating paravalvular leaks of transcatheter aortic valves: a critical appraisal.

Paravalvular leakage (PVL) is an important complication of transcatheter aortic valve implantation (TAVI). It contributed to the erosion of the clinical benefits of TAVI and confidence of its adoption as a default therapy in low surgical-risk patients. Newer TAVI technologies are provided with effective paravalvular sealing as well as retrieval/reposition mechanisms that are believed to considerably lower the risk of PVL. Meanwhile, developments in timely detection and accurate quantitation of PVL remain lagging behind those technological advances. The Valve Academic Research Consortium-standardized criteria of PVL assessment are based on echocardiography and are, according to experts' opinion, not adequately validated. Peri-procedural diagnosis, based on angiographic, haemodynamic, and/or echocardiographic methods, is so far without standardization of acquisition or interpretation. The aim of this report is to review the strengths and limitations of the current technologies used for PVL adjudication. Understanding this strengths/limitations ratio is important to define an appropriate scheme for detection and quantitation of PVLs both in clinical trials and in routine clinical practice.